• Title/Summary/Keyword: 2축피로

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Seismic Performance Evaluation on Bending Deformation of 2-Ply and 3-Ply Bellows Expansion Pipe Joints (2겹 및 3겹 벨로우즈 신축배관이음의 휨 변형에 대한 내진성능평가 )

  • Sung-Wan Kim;Sung-Jin Chang;Dong-Uk Park;Bub-Gyu Jeon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.2
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    • pp.33-41
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    • 2023
  • The application of seismic separation joints that can improve the deformation capacity of piping is an effective way to improve seismic performance. Seismic separation joints capable of axial expansion and bending deformation are installed where deformation is expected and used for the purpose of safely protecting the piping. Bellows are flexible and have low stiffness, so they can be used as seismic separation joints because they have excellent ability to respond to relatively large deformation. In this study, the seismic performance and limit state for bending deformation of 2-ply and 3-ply bellows specimens were evaluated. Seismic performance was evaluated by applying an increasing cyclic load to consider low-cycle fatigue due to seismic load. In order to confirm the margin for the limit state of the evaluated seismic performance, an experiment was conducted in which a cyclic loading of constant amplitude was applied. As a result of the experiment, it was confirmed that the bellows specimen was made of stainless steel and had a high elongation, so that the 2-ply bellows specimen had the limit performance of resisting within 3 cycles even at the maximum forced displacement of the 3-ply bellows specimen.

A Study on Control of Walking Assistance Robot for Hemiplegia Patients with EMG Signal (EMG 신호로 반신불수 환자의 보행 보조로봇 제어에 관한 연구)

  • Shin, D.S.;Lee, D.H.
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.7 no.2
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    • pp.55-62
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    • 2013
  • The exoskeleton robot to assist walking of hemiplegia patients or disabled persons has been studied in this paper. The exoskeleton robot with degrees of freedom of 2 axis has been developed and tested for joint motion. The obtained EMG signal from normal person was analyzed and the control signal was extracted from it for convenient and automotive performance of assistance robot to help hemiplegia patient walks as normal person does. the purpose of using FES(Functional Electrical Stimulation) for hemiplegia patient's walk is to restore damaged body function by this, but this could give fatal electrical shock to patients by wrong use or cause quick fatigue in muscle by continuous stimulation. The convenient movement of hemiplegia patients with minimum muscle fatigue was looked possibly by operation of assistance robot exoskeleton using control signal. and the walking assistance exoskeleton robot seemed works more efficiently than using FES stimulator. The experiment in this study was performed based on usual motion in our life like walking, standing-up, sitting-down, and particularly feedback control system using Piezo sensor along with button switch was applied for smooth swing motion in walking. The experiment also shows that hemiplegia patients can move conveniently by using electromyogram signal of healthy leg for the operation signal of assistance robot system attached at damaged symmetrical leg.

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The Development of Cement Treated Base Material with Restraint Reflection Crack (반사균열을 억제한 시멘트 안정처리 기층 재료개발)

  • Kang, Sung-Cheul;Lee, Kang-Won;Cho, Yoon-Ho
    • International Journal of Highway Engineering
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    • v.7 no.2 s.24
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    • pp.33-43
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    • 2005
  • This paper describes a new approach to minimize the amount of shrinkage cracking in cement treated base(CTB). CTB is a stiffness base having lots of merits such as higher rutting resistance, minimizing fatigue cracking, and the ability to distribute upper loads. However, It is not applied to asphalt pavement system in Korea because of possible cracks caused by dry shrinkage. The goal of this study is the development of cement treated base with lower shrinkage for preventing reflection cracks and rutting. After identifying factors affecting dry shrinkage and analyzing mechanism of each admixture, the laboratory and field tests were designed and performed. Through the preliminary tests, the mix design containing 25 percent o( fly ash and 7 percent of cement was suggested. This mix design was satisfied with strength for Korea specification standard. According to the results considering strength, shrinkage, and economical efficiency, two mix designs were selected; 1) containing 25 percent of fly ash and 2) containing 25 percent of fly ash with 10 percent of expensive additive. For field test based on the result of laboratory test, the optimized alternative in cement treated base with lower shrinkage was the mix design containing 25 percent of fly ash with 10 percent of expansive additive.

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Analysis of the Correlation between Human Sensibility and Physical Property of luminous Sources -Focused on Response according to Character of Color Temperature by luminous Sources- (건축조명광원의 광학적 특성에 따른 인간의 감성반응 분석 -조명광원별 색온도 특성에 따른 반응을 중심으로-)

  • Lee, Jin-Sook;Oh, Do-Suk
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.19 no.5
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    • pp.9-16
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    • 2005
  • The purpose of this research is to acquire emotional data on luminous source by measuring and evaluating human emotional response to the change of the optical feature of luminous environment Luminous sources used in actual architectural space were selected with the optical feature of luminous soured then to measure and analysis human emotional response on Luminous Source. As a result of that 1) In the result of performance measurement by the item of the clear vision of an optic function the fluorescent lamp of daylight indicated the most excellent Performance. 2) In the item of fatigue and stress, the metal halide lamp and mercury lamp showed the most 3) In $\ulcorner$ suitable in light$\lrcorner$, $\ulcorner$a similar with daylight$\lrcorner$ adjective of the amenity item the fluorescent lamp of daylight which color temperature was high turned up to be high also, in $\ulcorner$brilliant$\lrcorner$, adjective, the metal halide lamp and mercury lamp turned up to be low. 4) In the result of factor analysis, three factors $\ulcorner$activity$\lrcorner$, $\ulcorner$potency$\lrcorner$, $\ulcorner$evaluation$\lrcorner$ were abstracted and $\ulcorner$activity$\lrcorner$ factor has the most influential on evaluating the mood of interior space. 5) For the affection in the mood evaluation by each luminous sources, $\ulcorner$activity$\lrcorner$ factor was the most influential by metal halide lamp and fluorescent lamp of daylight, $\ulcorner$potency$\lrcorner$ factor was most influential by kind of incandescent lamp, $\ulcorner$evaluation$\lrcorner$ factor was most influential by fluorescent lamp of low color temperature.

AR-Geister (증강현실 기반의 가이스터 게임)

  • Kim, Jin-Gook;Kim, Byung-Chul;Lee, Hye-Sun;Lee, Jong-Weon
    • Journal of the Korea Computer Graphics Society
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    • v.13 no.2
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    • pp.31-38
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    • 2007
  • Recently, he trend of the game culture have been changed rapidly from offline games to online games. This change drives the advancement of online games, but it causes the standardization of the game culture. Few years ago, there was a rising interest in board games. Board cafes, place for playing board games, are spread over Korea rapidly because board games give players connectedness through direct social interactions that is lacking from online games. However, the board games lose their popularity because of their complex rules and expensive cost. In this paper, we would like to develop the system using Augmented Reality(AR) that could easy the problems caused by the complex rules of the board games.

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The Characteristics of Depression in Cancer Patients on Chemotherapy (항암제 투여 환자의 우울 양상)

  • Joo, Yeol;Seo, Wan-Seok;Kim, Jin-Sung;Lee, Jong-Bum;Cheung, Seung-Douk;Song, Shin-Ho;Bai, Dai-Seog;Lee, Kyung-Hee;Hyun, Myung-Soo
    • Korean Journal of Psychosomatic Medicine
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    • v.10 no.2
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    • pp.154-165
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    • 2002
  • Objectives : The purpose of this study was to identify characteristics of depression in cancer patients treated with chemotherapy. Methods : Subjects were 37 cancer inpatients of oncology in Yeungnam university hospital. BDI and ZDS were done and HDS was performed through semistructured interview. Results: 1) There were no significant differences of depression scale score according to sex, education, religion, marital status. 2) The mean scores of BDI, ZDS and HDS in 37 cancer patients were 18.27${\pm}$7.73, 36.51${\pm}$10.82, 15.14${\pm}$6.60, respectively. 3) HDS, ZDS scores were significantly higher in other cancer group receiving high dose chemotherapy. 4) Item score for depressed mood, diurnal variation(p<0.001), dissatisfaction(p<0.01), physical anxiety, decreased libido, sleep disturbance(p<0.05) were significantly higher in other cancer group than others. 5) Eight patients were diagnosed as having major depressive disorder, 11 as adjustment disorder, and 18 patients had no axis I diagnosis. 6) In major depressive disorder group, the score of the depressed mood item in ZDS was high (p<0.05). HDS item score for depressed mood, work difficulty, anxiey(p<0.001), psychomotor retardation(p<0.01) were significantly higher in major depressive disorder group. 7) In patients with adjustment disorder, ZDS item score of constipation(p<0.001), fatigue, anorexia (p<0.01), emptiness, sleep disturbance, dissatisfaction, weight loss(p<0.01) were high. HDS item score of hypochondriasis(p<0.01), agitation(p<0.01), fatigue, decreased libido(p<0.05) were significantly higher in adjustment disorder group. Conclusion : Some psychiatric disorders, such as adjustment disorder and major depressive disorder were common in the cancer patients in chemotherapy. Psychiatric intervention will increase compliance of cancer treatment and improve the quality of life. This study suggests that it would be important to consider the nature of somatic symptoms in diagnosing depression in cancer patients.

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A Study on the Relationship between the Disc of Least Confusion and Corrected Vision of Astigmatism (난시안의 최소착락원과 교정시력과의 관계 연구)

  • Kim, Jung-Hee;Kim, In-Suk
    • Journal of Korean Ophthalmic Optics Society
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    • v.13 no.2
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    • pp.51-57
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    • 2008
  • Purpose: This study has been conducted to know how the size and position of the circle of least confusion has an influence on the vision for minimization of asthenopia when astigmatism is corrected and appropriated prescription to provided clear vision life. Methods: The method of the study has been worked on 68 students (136 eyes) of man and woman enrolled in university of Gyeong-gi-do aged 20 to 40, who have myopic astigmatism in order to know how the corrected vision changes according to the size and position of the circle of least confusion of astigmatism, the vision has been tested by giving the vision whose astigmatic power of 0.25D and 0.50D was just reduced, low correcting the astigmatic power into 0.50D, and at the same time inserting additionally spherical power -0.25D, all under a condition that the corrected vision after completely corrected astigmatism, and the axis of astigmatism was not changed. Results: The average vision was 1.047 when the astigmatic power was fully corrected, and in low correction of 0.25D, it was 0.914, and in low correction of 0.50, it was 0.772. It has been learned that the bigger the circle of least confusion was the bigger the range of vision reduction and the corrected vision in astigmatism has correlation with the size of the circle of least confusion. It has been examined that the average vision according to position of the circle of least confusion in astigmatism was 1.047 when the astigmatic power was completely corrected and focused on the retina with state of point, and in case that the astigmatic power was 0.50D of state of low correction, that is, the circle of least confusion was focused before retina, it was 0.828, and it was also 0.826 when the astigmatic power is low corrected with 0.50D and the circle of least confusion was focused on the retina. Explained briefly, It has been examined that in case that the state of low correction of the astigmatic power was same, the vision reduction was less in the image of the circle of least confusion focused upon the retina than in the image of its being focused before the retina. Conclusions: In case that the refractive power of cylindrical lens is reduced in test of wearability in astigmatism, there needs surely an adjustment of spherical lens that can place the circle of least confusion on the retina.

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